Means for damping lithographic-printing surfaces



3 Sheets-Sheet 1,

(No Model.)

Jpwi OSBORNE. MEANS. FOR DAMPING LITHOGRAPHIG PRINTING SURFACES.

Noi'338,769. f Patented Mar. 30

Q yea/27;";

1 3 Sheets-Sheet 2.

J. W. OSBORNE; MEANS FOR DAMBINGLITHOGRAPHIO PRINTING SURFACES.

To all whom it may concern:

several folds sewed. Such rollers are inherently 1 'UNITED STATES PATENT Ome JOHN \V. OSBORNE, OF WASHINGTON, DISTRICT OF COLUMBIA.

MEANS FOR DAMPIN SPECIFICATION forming part oi Letters Patent No. 338,169, dated I Applieationjilcd September 16, 1881. Serial No. l lilil. lNomodel.)

Be it known that 1, JOHN W. OSBORNE, of Washington, District of Columbia, have invented a new and useful Improvement in the Meansfor Damping Surfaces Prepared for Printing in the Lithographic Manner, of which the following is a specification.

My invention is related to the devices now in use for the'deposition of an even iilnrot' water upon lithographic stones and zinc or calligraphic plates, which is necessary before "such surfaces can be inked and printed from, and to the manner of making such deposition; and it is especially-applicable in pow er-presses for lithographic and similar printing. In presses of this kind the damping of the print ing=surface in the actual practice of the art at the present .daf, is almost universally per formed by rollersconstrncted for the purpose. These rollers are generally held in stationary bearings, and having received the necessary quantity of waterfrom a suitable fountain, or in some other way, they transfer it to the printing'surface as they rollover when, in the working of the press, it passes beneath them. 'Damping-rollers for this use are made by covering a suitable spindle with material till the of some fibrous desired thickness is obtained, over which an outside covering of cotton or linen cloth is V I defective 'inopemtion, becausewhen wet, and especially after having beennsed for a short time, they become very hardand unyielding,

and subject the printingsurface to an n udesirable amount of rough treatment, and because it is practically impossible with them to damp the edges of the stone or other printing-surface so as to insure those parts against takiu'g ink from the inking-rollers, as all other non-printing parts areinsured. If to attempt the damping of the front and back edges of a lithographic stone "as it lies on the carriage of a reciprocating press the rollers are lowered so that their surfaces are tangents to a plane below that of the face of the stone the edges ofthe latter strike the rollers aheavy blow at the moment of their contact with it, and they have to rise instantly out of the way. The tendency hf such a blow is to stop the rotation of the rollers to a greater or less extent, and, conjoined with the sudden rise, (for which provision niust be made in the "practice it is the same, i

G LITHOGRAPHlC-PPRINTING SURFACES.

March 30, 188 6.

roller-bearings) it produces an amount ofjar and vibration which is detrimental, so that in an expedient which is used but very slightly for the reasons given, and because thedaluping of the edges so accomplishedis by no means as effective and certain as that of the flat surface which receives no blow and on which the roller travels at the proper surfaee-' speed. Further-morathis expedieutflneificient and unreliable as it is well known to be as far as the front and back ed ges are concerned, is quite useless as a means for protecting the side edges, there being no way to get enough of water upon them by roller damping of which I am aware, excepting, perhaps, that of using a great and damaging excess on the surface generally. Accordingly incessant attention is demanded on the part of the workman, and frequent hand-dampening of the edges when a sheet is printed which overhangs the stone, if its margin is to be kept,clean. I overcome the imperfections in damping here indicated by applying the water'to the print ing'surface through the intervention of a roller which remains at all times elastic and soft,

and which reaches all the edges of that surface very efficiently. In general terms I constructsuch a roller by inflating a long cylinder of pliant, impervious material of such character that it does not appreciably stretch or elongate under anystrains encountered in practice with air or other fluid, covering the same with absorbent cloth of a suitable kind to hold and apply the water, and

causing the whole to revolve upon a suitable axis over the printingsuriace to be damped; and my invention Iurther consists in an iinroved means for supplying such an apparatus for lithographic, zincographic, ligraphic damping with the requisite increments of water to stunt amount, so as to compensate for that which is removed at every revolution of the press; This operation, wheninade automatic in lithographic powerpresses, isusually accomplished by taking the water by means of a vibrating roller froni the'surface of a revolving fountain-roller to that of a rider upon the damping-rollers. The apparatus for-this purpose occupies considerable space, and sev keep it charged with a con;

eral movements and adjustments have to be accomplished. In my apparatus 1 deposit the exact quantity of water from tube provlded with a large number of orifices directly upon the,dampiug/apparatgs in-a manner to be more fully set forth in the following.

In the drawings, formicg part of this speci:

fication, Figurel represents in plan a portion of a reciprocating lithographic: power-press in'which the stone isishown in position with an inflated. roller crossing it and the tube from which the supply'of' water is obtained.

- Fig. 2 is an elevation oi: the damping apparatus with parts of the'press and the stone. Fig. 3is a side elevation of the same. Fig. 4 is a cross-section of the damping-roller and rider and of the water-tube or fountain in relative positions. Fig. 5 is a similar cross section with damping-roller and'rider's depressed, showing their relation to the stone.

Fig. 6 shows a cross-section of adistorted damping-roller with a single riderand watertubeor fountain. Fig. 7 is a longitudinal section of. the same damping-roller, showing its construction and its relation to the stone with the rider and water-tnbedn elevation.

In the other figures this is unnecessary, both .sides of the press and the damping apparatus being thesame, except that the rack and gearing which drives the rollers are only required upon one side, which is that represented.

' The sca-le of Figs. 4., 5, 6, and 7 is double that of those preceding them.

h as

. .of the riders lying on the driven.

" ing-roller e,-

3 e'is the damping-roller; The latter are driven'by the rack g throughthe intermediate wheel, h, I

gearing into the wheels i i, and by the friction It willbe seen that the intermediate wheel, h, runs free upon, the outside of the sleeve in, which forms a bearing forthe dampbe made fastnpon the spindle of that roller,

and the same may then'be driven directly, as well as the riders, the sleeve is in that case acting as a bearing for roller'e only,'and ex tendinginside the bracket d, just enough to form its flange.

In Fig. 2 the relative positions of the damping-roller, rider, and stone are assumed to be those showninFlg. 4. The diameter of the ridersis the same'as that of the pitch-line of the gears i i which drive them, and therefore the surface-speedof the rollers will be the same as that of the it rolls; but when the roller 9 and its yiders are in the relative positions shown it Fig. 4, the pitch-lines of the rack and intermediate inside, the roller e will the disk r, is to have.

In Fig. 1 the full width of=the press is show n.

Thebrack ets d d,

1 preventedfrom turning diameter of the flexible tube so strained is roller 2, that also is but, if it is .desired, wheel h may.

tube w, and the flexible hose 9,

printing-surface over which asaile wheel, h, and of that wheel and the wheels 1' i on the riders. are somewhat apart. Ifall the rollers be now lowered till the pitch-lines coin Fig. 5, but its surface-speed will still be the same as that of the stone cthat is, its riders will drive its distorted periphery at their own surface-speed, which is that required to cause the damping-roller to perform its office without drag or slip. The proper adj ustl i m'ent of the roller 6 is controlled bythe setscrew 1,- that of rolls f f by screwsmm. When in their proper places, the I roller bearings are clamped fast by'the screws n and o 0, re-

take the form shown I spectively, as in my inventiomno provision is This advantage struction of the damping-roller 0, one end of which is shown in longitudinal section in Fig. 7. The spindle p has the collar q clamped upon it in suitable position, outside which is A parallel tube of strong, pliant, yet non-extensible material, 3 (such as oilcloth'or printers blanket made of cloth and required fora jump or rise of these rollers. is due to the peculiar conof the full diameter'which theroller rubber) is fastened to the recessed edge of the disk r by means of metal segmets retained by screws, asshown, or in other suit-able man ner. The other end of this roller is a duplication of that described, and tube is fast to both disks they are forced asunder by means olithe three setscrewst t t in either end, so as to strain the tubular part tight and give it its truecylindrical shape.

when the pliant The extremities of these set-screws, turned smooth; fit into and enter three corresponding cavities in the collar q, whereby the disk 1' is somewhat less than'that of the finished. roller to admit of its being covered with several folds of absorbentmaterial, u-suchas canton-flannel, &c .to hold the water used for damping. This is sewed on in the usual way,gand it is best applied before the flexible tube is made to the disks,when' it by a temporary mandrel. One end of the spindle p is bored through its length for some where cross-opeddistance past the collar 'q,

on'the'spindlep. The

can be supported insideings connect the tube so formed with the inside ofthe roller. Whenv the latteris in position, the outside end of the spindle (pierced with radial holes) has slipped over it the recessed annular bearing 1;, which terminates the In this way the'hollow interiorof the roller 1; is at all times in tubular connection through with thereceiver z. This receiver is a closed vessel, in which air at a constant pressure is maintained by means of a pump or suitable blower, the adjustable valve a serving to regulate the same by lifting whenever the desired pressure is exceeded, which may, take place at every" revolution of the press. A very small pump is suificient. for this purpose, and it may be conveniently connected with some moving tube 11;, and thisis held in place by theboltzt.

supply thesmall quantity of air which leaks from the roller or its imperfect connections.

The pump may also be made to accomplish.

the constant distention of the roller.without the interposition of the receiver 2; but I preferthe large supply of compressed air,'and' it is particularly convenient to effect the inflation of the-roller in the first instance. viously the receiver 2, though shown with the press, and the pump which supplies it may be placed at any desired distance, and one such receiver can be readily made to in" flate all the-damping-rollers of a large number of presses. The pressure in the roller holds its flexible surface distended, and efi'ects the general distribution of any local.

force calculated to distort its cy lindical formas,- for instance, the contact ofthe stonewhich necessarily flattens a part of its periphery, in the manner shown in Figs. 5 and 6. The effect of the increased air-pressure inside the roller is also toeause it instantly to resume thecylindrical form when the cause,

otdistortion has been removed. Thus, when the front edge of the stone reaches the roller the latter is perfectly cylindrical, and, being below the level of the printing-surface,it strikes a little below the edge with a soft blow. As the stone proceeds it flattens upon its face, and when the roller leaves the.hack

'edgeit instantly expands and damps that edge also.

Fig. 6 illustrates at -b what takes place at the time of contact with either edge. The side edges of the stone are likewise touched by this damping-roller, because beyond the flattened part in contact with the printing-surface the cyliudrical form of the roller on each side is restored, and in doing so it expands to some distance downward enthuse edges, as shown in Fig. 7 at 0.

In place of air other fluids can in a damping-roller, as herein described-as.

for instance, water. The roller bei ng once .filled with water it iskeptfnllunder pressure by'introducing water into. the lower pai't'of the receiver 2, and continuing the pipe or hose 'yfroni thetube w downward inside that vessel, asindicated by dotted lines, so that the pressure of the air shall force the water to ascend.

. appreciable interval of time on every part of t This modification accomplishes results similar to those, already described. I With a rollerso tilled it is possible and advantageous in some cases to work-withaut'a rider, lorthe'weight of the water causes the flexible tube. forming the surface to be damped is an important advantage, giving the water abundant opportunity to pass over, which is not the case when sea-159 part of the press. All that is necessary is-to be employed which exerts the, pressure directl the usual solid rollers are used. As a "conse quence one-roller will be found in most cases quite. snfficient, though obviousl y two or more maybe employed. I i

The functionof the rider ,or riders in my invention is to communicate motion directly to the pliant surface of the damping-roller and hold it in contact with the printing-surface. The pressure they exert upon the inflated roller also tends to increase indirectly the pressure on the stone, and the distortion they efl'ect tends to increase the depression of the ldwer convex surface when the roller is off the printingsurface, and to increase the size of the flattened segment on its lower side when it'is over the work.

which isnecessary to effect the plOpBIdttl'llping of the edges of the printing-surface. This is important when thel'lamping-roller is driven directly, l'orin that'case its diameter should be exactly that of the pitclrline of the wheel that drives it, and under those circumstances to drop it involves either crossing the pitchlines of the rack and wheel or lowering the former, which is undesirable, because the same rack-is commonly used tov drive the inkingrollers. It is also a practical and serviceable method when the damping-roller and its rider or riders are driven. not by gearing, but by friction rollers or trucks running on smooth bearers in place of 'a rack, as is done inmany forms of lithographic press. t

- The weight of the. rider or riders used in the method of damping I have invented is not a matter of importanca'because' their beari ng sare ,clamped fast; hutriders with loose beatings-may be nsedshould they be convenientl'yavaiidable without essentially modifying eourse,- affectingthe result. With fixed bean lhese results are eliected when one rider only is used, as in Figs. 6 and .the principle involved, their -weight-then, of

ings the riders maybe as light as iscousisteut withstrength and ,sti flness,}fwhich is anon venience iahandling and mother. ,ways., ,U der these cirbuhis'tances noise 'ndvibration. are prevented, "and bllQpleSSflfe ex [ted on, the, pn' ntiftg -surlace i'sftiuite, under control, :hein'g adj uisl'abia altogether byincreasing or decreassionol' the springginthe'yalve'a e air or other'iinidin "on the printingsurface and not the weight of the roller'or the rider upon it, although therlatter furnishes a line of resistance and reacts against the'forcefrom.within; it will also be found "that with a constant pressure in the receiver that upon the printing-surface will bethesame no I the roller same rider is used on ordinary damping-rollers it is inversely proportional to the width,

- increasing as the latter becomes less.

Y woven canvas, which, when wet, will befound plied from the receiver.

be understood thattheinside of the roller must It may further be said with regard to the construction of the damping-roller that the principle involved can be very well carried out by making the flexible envelope of thin metal, as copper or brass; also, that material notquite impervious to air can be used for the same purposesas, for instance, closelyimpervious enough to. allow of the maintenance of considerable pressure within it,while the leakage which takes place is easily sup- Nor do Iwish it to be left empty. On the contrary, to save the flexible envelope from the. injury caused by accidental blows and careless handling theinside may be loosely filled about thespindle 'with wool or hair or-similar substance, as showuinFigs. 6 and 7 atj; but this must be so as not to interfere with the free distortidn of the-envelopeto the required'extent and its immediaterestoration to the cylindricabform when the-disturbing cause ceases to act; nor should it hinder in the least the free movement otZthe air. or other fluid with which the roller is held distended, or the immediate propagation of the force emanating from the receiver or pump to all parts of the inuersur- For the purpose of maintaining the neces saryamouht of water in the absorbent covering of the damping-roller when it is in useL empty the water tube or fountain d. ,Thistube crosses the press over the damping apparatus,

usually over and parallel to a riding-roller. It is made of a heavy brass bar 'for the sake of strength, and is bolted to thebraekets at each It is stopped at-one end, and at the other isin comside. The bore of this tube is small.

munication with the tube e, which is held tightly to it by means of the hollow boltfi. The whole length of the water-tube-d in the part which crosses the rider'is pierced radially by a close row of exceedingly-miimte holes,

(seen in cross-section in Figs. 4, 5,-and 6.) the diameter of the holes being so small that the water will be retained therein by atmospheric pressure and capillary attraction until forcibly ejected. This is a feature of importance, in

that it prevents the tube from being drained or emptied, the tube remaining constantly filled, so that it responds instantly at. the proper time, in consequence of which a uniform and definite quantity of moisture is delivered at each action of the apparatus. are directed downward, and between them the metal may be filed away in the manner seen in Fig. 2; or each little hole may be bored in a separate nipple and screwed int-o the watertube in the manner shown in Figs. 6 and 7, the object being to prevent the running together of the ejected water into large drops,.-which result may also be accomplished by forcing the water out under'considerable pressure. The

These holes 7 tube 0 communicates with a closed receiver 9", and it descends inside nearly to the/bottom, as indicated by the dotted lines in Fig. 2, Into the receiver g" (which is constructed like receiver 2) a quantity of water is introduced,

receivers and zare the same, one receiver can be very well made to answer both purposesnamely, the ejection of the water and the inflation of the roller; but I prefer in practice to usetwo, because it is not always desirab'letqhave the same pressure for both operations. well employed, letting the escaping air fr0;n the receiver in which the greater pressure is required enter the other, ter which passes upward through the tube e" and isejected in, little drops from d through the openings over the rider is very small for each revolution of the press. It is controlled by the cock h". This'is opened and closed periodically and automatically in any convenient manner, and lorit a suitable valve may be substituted, it'desired. In the drawings the lejoint with the rod ifl'rom a cam. The point of attachment and the length of the cam-rod" are adjustable while the press is running, and can be clamped fast in any'position by the setscrews at k". In this way the duration of the fiow of water (which in all cases is very short) is under control, and as the water-tube remainsv always full precisely 'the quantity of water which passes the cock 'h is thrown out One pnmp,'however, can be very- The amount of waupon the roller. It isladvisable, unless the water usedfor damping is very pure, to filter it at each filling ofthe receiver, so asto prevent the lodging ofany impediments i n the minute openings of the watertube. I wish it also to be understood that while I regard the use of areceiver containing water under pressmeets the most convenient way of ejecting the required water on the damping apparatus I do' not regard that device as indispensable, for it is plain that a small force-pump with variable stroke maybe directly connected with the water-tube d wherebythe prompt and decisive ejectment of the proper quantity may be accomplished; but my experience convinces me that in most cases the elastic pressure exercised by compressed air, as herein set forth, is sin1-- of obtaining the requisite force.

The'water as it issues in minute streams from the orifices in'the water-tube d may be repler and preferable to that and other methods ceived directly upon the rider, asiu Fig. 6; or

it may be allowed to fall upon the roller, or

upon a small flap of cloth attached to one side ot'the-"water-tube and exte'ndingdown to the rider, which is shown in section at 1 in Fig. 4,

or upon a loose covering of the same material,

embracing the tube, as m in Fig. 5, and which may beregarded as a double flap, both of which devices tend to effect a distribution of the water before it reaches the rider. by the capillary action which takes placesin the cloth, an action which is also very decidedin the absorbent coveri ngon the roller itself, and which the pressure of the riders still further promotes.

\Vjth regard to distribution, it may also be said that the best time to project the water upon the damping apparatus is immediately after a damping has been effected, as a considerable interval then elapses before the damping-roller is again called upon to perform its function, during which capillary distribution takes place.

By the terms surface and printing-surface, herein employed,ismeantalithographic stone or bed, a zinc bed, or equivalent bed prepared for printing in the lithographic manner, this being the common meaning of, these terms as used in the art at the present day."

Having thus described my in vention, what I claim, and wish to secure by Letters Patent,

1. In a lithographic machine. the combination, with a bed or surface for printing in the lithographic manner, of a pliant damping-rod er containingair or other fluid under pressure, and mechanism,substantially as described, to cause said roll to act forcibly upon the printing-snrface. I

2. In a lithographic-printing machine, the combination of a bed carrying a stone or surface adapted for printing in the lithographic manner, a pliant dampingmoll filled with air or other fluid under pressure, and one or more riding-rolls, substantially as described.

3. In a lithographic-printing machine, thecombination of a horizontal tube providedwith minute orifices adapted and arranged to retain water by capillary attraction and to deliver the same upon the surface, and means, substantially as described, for effecting the forcible and positive ejection of the water from said orifices at suitableintervals.

4. in a lithographic-printing machine, the combination of the water-tube d", provided with a row of minute openings, the rider, and

an intermediate flap, 1, whereby the uniform distribution of water is secured.

JOHN W. OSBORNE.

\Vi tn esses:

L. BACON, f V H. 0. HUNTEMANN.

Corrections in Letters Patent No. 338,769.

It is hereby certified that in Letters Patent No. 338,769, granted March 30, 1886, upon the application of John W. Osborne, of Washington, District of (Jolumbia, for an improvement in Means for iJamping Lithographic-Printing Surfaces, errors appear in the printed specification requiring correction, as follows: In lines 11 and 91-2, page 1, the word calligraphic should be stricken out and the word collogmphio inserted; in line 36, page 4, the word empty should be stricken out and the word employ inserted; and that the Letters Patent should he read with these corrections therein that the same may conform to the record of the case in the Patent Offioe.

Signed, countersigned, and sealed this 6th day of April, A; D. 1886.

min} H. L. MULDROW,

Acting flecretairyhof the Interior. Gountersigned M. V. MONTGOMERY,

Commissioner of Patents. 

